On May 6, 1937, the Hindenburg balloon - the pride of Germany - exploded into a large area of Lakehurst, New Jersey, and the United States was engulfed in smoke and fire.
Human history has recorded extremely horrific explosions in both its strength and its consequences. The explosion in Tianjin, China last though terrible but not the most feared.
The long-standing mysteries always attract the attention of many curious people, and are even more concerned when the solution is gradually revealed.
The US Aeronautics and Space Agency (NASA) is building a new generation balloon to transport goods - the project is considered a revolution in the transport industry.
This horrific accident killed 35 people out of 97 people on board and ended the era of hot air balloons.
What remains of Hindenburg, the world's largest balloon, is being kept in a giant hangar near the capital, Rio de Janeiro, Brazil.
If we consider protein to be a specific substance of life, water is an indispensable environment for life to function.